Jujube trees, also known as Ziziphus jujuba, are deciduous trees with thorny branches. A 'fence green hedge' typically refers to a hedge made of greenery, often used for landscaping. The image you mentioned would likely depict a hedge formed by jujube trees, showcasing their lush foliage and possibly their thorny nature. Jujube trees are known for their medicinal properties and are cultivated for their fruits as well as their ornamental value.